Location of the binding site for the allosteric activator IMP in the COOH-terminal domain of Escherichia coli carbamyl phosphates synthetase.

Abstract

Using UV-irradiation we cross-linked IMP, the allosteric activator of E. coli carbamyl phosphate synthetase (a heterodimer of 117.7 and 41.4 kDa subunits), to the large subunit of the enzyme. As in the native enzyme-IMP complex, the cross-linked complex was resistant to attack by trypsin. Thus, IMP is attached to its normal site and induces the normal… (More)